[ROY4]

Hello everybody

I'm somehow new to coding in CFX and I want to learn about CCL and CEL. I have read about them in CFX tutorials but it is somehow vivid for me. I would like to know:

- What is the difference between CEL and CCL?
- Is CCL similar to UDF in Fluent or does it differ?
- In order to write a CCL and use it in CFX, do I need to install visual basics on my system just like the UDF?

I know that these questions might seem really basic. However, I would appreciate if someone can be patient and explain it to me.

Thank you in advance

[Opaque]

CCL is not a programming language, but a state language.

CEL (notice the difference) is an expression language that

- allows the writing of mathematical expressions (with only 1 logic statement, If) without the need for a compiler.
- it has predefined mathematical functions: sin/cos, sinh/cosh, sqrt, log, etc.. (see documentation for details)
- it has access to a set of exposed solution variables that you can use directly in the expressions
- there is no array syntax since it is hidden by the local context the expression is evaluated at, what is that
- If you are evaluating say temperature^2 on a boundary, it will evaluate the expression on the faces of the boundary (all of them, or in groups of them)
- If the same expression shows up on the domain level, say initialization, it would be evaluated on all the nodes/vertices of the mesh associated to that domain w/o saying temperature(1:n)^2 or looping structure like for, or DO.

If you exercise the tutorials, you can get a feeling for it.

[ROY4]

Originally Posted by Opaque

CCL is not a programming language, but a state language.

CEL (notice the difference) is an expression language that

- allows the writing of mathematical expressions (with only 1 logic statement, If) without the need for a compiler.
- it has predefined mathematical functions: sin/cos, sinh/cosh, sqrt, log, etc.. (see documentation for details)
- it has access to a set of exposed solution variables that you can use directly in the expressions
- there is no array syntax since it is hidden by the local context the expression is evaluated at, what is that
- If you are evaluating say temperature^2 on a boundary, it will evaluate the expression on the faces of the boundary (all of them, or in groups of them)
- If the same expression shows up on the domain level, say initialization, it would be evaluated on all the nodes/vertices of the mesh associated to that domain w/o saying temperature(1:n)^2 or looping structure like for, or DO.

If you exercise the tutorials, you can get a feeling for it.

Dear Obaque
Thanks for your helpful answer. If I want to use a new drag model in the simulation of multiphase flow (a model other than Ishi-Zuber, Schiller-Naumann, Grace), How should I enter that model in CFX?
This model uses Re number which needs to be calculated

[ghorrocks]

Most new models can be implemented as CEL. If it is too complex for CEL you can use user fortran routines.

[ROY4]

Originally Posted by ghorrocks

Most new models can be implemented as CEL. If it is too complex for CEL you can use user fortran routines.

Dear ghorrocks
I have used simple CEL in CFD Post before, but not in CFX-Pre. If I want to enter a model which contains bubble diameter based Reynolds number, then am I able to use CEL?

In order to use CEL, should I write a special form of code or I just need to write the formula?

Do you have any reference or can you please tell me how I can enter my user Fortran code into the simulation?

[ghorrocks]

Only consider user fortran if what you want to do cannot be done in CEL. Always try CEL first.

CEL is described in the CFX documentation, in the reference manual. There is a variables and function guide in there.

[ROY4]

Originally Posted by ghorrocks

Only consider user fortran if what you want to do cannot be done in CEL. Always try CEL first.

CEL is described in the CFX documentation, in the reference manual. There is a variables and function guide in there.

Is there also a manual for user Fortran?

[ghorrocks]

Yes, in the solver modelling guide.

How about for the next one you try looking in the CFX documentation to find these things yourself? The search function finds stuff pretty quickly in my experience.

[ROY4]

Originally Posted by ghorrocks

Yes, in the solver modelling guide.

How about for the next one you try looking in the CFX documentation to find these things yourself? The search function finds stuff pretty quickly in my experience.

Dear ghorrocks,

I don't have access to all CFX manual guide, I just have the Tutorials and its just vivid for me. I'm so sorry for asking you obvious questions and Thank you for answering them.

[ghorrocks]

http://lmgtfy.com/?q=cfx+documentation